TH425 adapter

[magilla]

My Karmann Ghia project utilizes the drivetrain from a 1970 Oldsmobile Toronado GT (455cid with a TH425 transmission). Of late, I've been torn between building the 455 or swapping it out for an all-aluminum LS-style motor, as I'm rethinking how I want to proportion the weight bias fore and aft - and using an all-aluminum motor would help. The Olds 455 only weighs about 50-lbs. more than a smallblock Chevy, and I am planning on going with Edelbrock aluminum heads & intake, so that will help in reducing weight. The other factor I have to reconsider is using the Toronado drive axles - compared to 'Vette halfshafts/uprights/calipers, etc., these puppies are heavy. The biggest obstacle I'm facing in going to an LS-style motor (or any motor) is the adapter plate to mate it to the TH425. Has anyone ever heard of the TH425 being used with a different engine, or anyone making adapter plates for oddball engine/tranny combos?